Oxygen Reduction Reaction on Pt/C Catalysts Prepared by Impregnation and Liquid Phase Photo-Deposition

Abstract

Pt/C catalysts supported on carbon (5 wt.% Pt) synthesized by photo-deposition and impregnation methods were electrochemi- cally evaluated in the oxygen reduction reaction. Platinum nanoparticles were prepared by photo-irradiation of Pt precursors (H2PtCl6 and C10H14O4Pt) with UV-irradiation (365 nm) at room temperature. The photo-reduction of H2PtCl6 to metallic platinum (Pt4+→Pt2+→Pt0) was faster than C10H14O4Pt (Pt2+→Pt0) at the same operation conditions. The Pt/C samples were characterized by XRD, EDS, H2 chemisorption, TEM, cyclic and linear voltammetry techniques. XRD and TEM/EDS studies showed that Pt particles synthesized with C10H14O4Pt by the photo-deposition method were smaller with a higher dispersion on carbon than those prepared with H2PtCl6. A similar behavior was found when the impregnation method is used. The platinum particle size was smaller with C10H14O4Pt as compared to H2PtCl6 precursor. The Pt/C catalyst synthesized with C10H14O4Pt by the photo-deposition method displayed a catalytic activity in the oxy- gen reduction reaction comparable to a commercial 10 wt. % Pt/C, ETEK catalyst.